Substance use problems are highly prevalent among persons living with (PLWH) in the United States and serve as serious barriers to engagement in HIV care. Yet, in contrast to studies of single substances, little is known about patterns of polysubstance use in this population. Moreover, other risk factors (e.g., financial hardship, incarceration, homelessness, and mental health distress) are also prevalent and complicate HIV management. The present study drew on a cross-sectional survey with African American/Black and Latino (AABL) adult PLWH from low socioeconomic status backgrounds in New York City who were insufficiently engaged in HIV care and evidenced detectable HIV viral load (N = 512). We used latent class analysis (LCA) to explore patterns of polysubstance use and their relationships to financial hardship, incarceration, homelessness, and mental health. LCA yielded three substance use classes: Class 1, a high polysubstance use/high-risk substance use class (9%); Class 2, a polysubstance use/moderate substance use risk class (18%); and Class 3, a moderate polysubstance use/moderate-to-low-risk substance use class (74%). Mental health symptoms were prevalent in all classes, but Class 1 had greater mental health distress than the other two classes. Current homelessness was more prevalent in Classes 1 and 2. We cannot end the HIV epidemic without engaging and treating AABL PLWH who have serious barriers to engagement along the HIV care continuum, and who evidence polysubstance use along with co-occurring risk factors. Clinical settings can develop outreach and engagement approaches to bring this subpopulation of PLWH into care settings, and further, specialized services are needed to successfully screen, treat, and retain them.